1. Field of the Invention
The present invention relates to an improved apparatus and method for separating blood components from blood by means of sedimentation action due to gravitational force.
2. Description of the Prior Art
Blood comprises a plasma component and a blood corpuscle component containing erythrocytes, leucocytes, blood platelets and the like. Recently, remarkable developments in so-called artificial organs have led to the practical use of therapeutic treatment in which blood is removed from the human body by extracoporeal circulation and subjected to a dialysis treatment or an adsorption treatment after fractionation. Such therapeutic treatment has become more and more important. It is strongly required, however, that it does not adversely affect the body. For this reason, the apparatus for the therapeutic treatment must satisfy various factors. One of these factors is that the apparatus should not remove the protein components contained in the patient's blood. For example, an artificial kidney should not discharge plasma protein along with the waste liquid.
Recently, it has been learned that an abnormal increase of high molecular weight solutes such as immune complexes, cryopricipitates, aggregates of immuno-globulin and nucleic acids in blood strongly influences the occurence and condition of autoimmune diseases. Therefore, plasma exchange therapy is carried out to remove said high molecular weight solutes.
Furthermore, in the field of blood transfusion, hospitals have not been transfusing collected blood whole, but have been frequently separating the collected blood into its components so as to use the specific blood component required by the patient. One method of doing this is to allow the blood to stand, wherein the blood corpuscle component gradually settles to the bottom and separates from the plasma. However, this gravitational method of separation is very slow. For this reason, hospitals have heretofore widely used centrifugal separation for separating blood components rather than gravitational separation. Centrifugal separation, however, is disadvantageous in that it requires an expensive centrifugal separator, which in turn requires high rotational power and safety devices.
Accordingly, the objects of the present invention are to eliminate the above-mentioned disadvantages of the prior arts and to provide an apparatus and method for effectively and efficiently separating blood components, without using centrifugal force, by means of sedimentation action due to gravitational force.
Other objects and advantages of the present invention will be apparent from the description set forth hereinbelow.
In accordance with the present invention, there is provided an apparatus for separating blood components by means of sedimentation action due to gravitational force, comprising:
a first empty space provided with an opening for a feed line of blood;
a component separation portion in connection with said empty space, the inside of the separation portion forming a plurality of flat or tubular blood flow channels; and
a second empty space provided with at least two openings for discharge lines of the separated blood components.
In accordance with the present invention, there is also provided a method for separating blood components by means of sedimentation action due to gravitational force, comprising the steps of:
continuously passing blood to be separated through blood flow channels comprising at least two flat or tubular empty spaces, said blood containing an added water-soluble polymer, while the blood flow channels are filled up;
separating the blood flow into multiple streams of the separated blood component layers; and
collecting the desired blood component layer or layers.